# Einstein's Cross: Examining the Impact of Lensing Galaxies

• Hydr0matic
In summary, the conversation discusses the phenomenon of gravitational lensing, where a distant quasar's light is bent and produces multiple images due to the gravitational pull of a nearby galaxy. The lensing object does not have to be rectangular, as it can still produce distinct images if the alignment is just right. The images are not circular as one would expect, but rather four distinct points due to the slight off-alignment of the quasar. This can cause the other details to get lost in space or be overshadowed by the brightness of the lensing galaxy.

#### Hydr0matic

Tell me if I've got this right ... The light from a distant quasar is bent around a more nearby galaxy, which is acting like a lens producing multible images of the quasar.. correct ?

What's up with this ? Is the lensing galaxy rectangular ? Why is the "lensing effect" producing four distinct images and not some distorted circular patterns ?

It's not rectangular, the lining is just that good, it is an oddity, but one that sheds a lot of light, no pun intended, on gravitational lensing.

The lining could be perfect and the lensing effect still shouldn't look like that... If the lensing object is spherical it should bend the light from an object behind it equaly in every direction, which will create a "circle of light" around the lensing object, not four distinct copies in a crossformation. Am I mistaken ?

Last edited:
You took my meaning of lining wrong, its not a straight line, the quasar in the back is off alittle bit, which creates the four points. Actually the light is bent spherecly, but due to the alignment, it peaks at four points, and the other stuff gets lost in space. That is it is so small it doesn't show up, and if you increase the exposure time, the galaxy in front will saturate the image.

Ok, I see... thnx !

## 1. What is Einstein's Cross and why is it significant in the study of lensing galaxies?

Einstein's Cross refers to a unique and rare phenomenon in which a distant quasar is lensed by a foreground galaxy, resulting in four distinct images of the quasar. This is significant because it allows scientists to study the properties of both the lensing galaxy and the quasar in great detail, providing valuable insights into the nature of lensing galaxies and the effects of gravitational lensing.

## 2. How does gravitational lensing occur in the context of Einstein's Cross?

Gravitational lensing occurs when the massive object of a foreground galaxy bends the path of light from a more distant object, such as a quasar, as it passes by. This bending of light creates multiple images of the distant object, as seen in the case of Einstein's Cross. The amount of bending depends on the mass and distribution of the lensing galaxy, allowing scientists to study these properties.

## 3. What can we learn about lensing galaxies from studying Einstein's Cross?

Studying Einstein's Cross allows scientists to learn about the mass and distribution of lensing galaxies, as well as their dark matter content. By analyzing the properties of the multiple images of the quasar, scientists can also measure the strength and shape of the gravitational lensing effect, providing insights into the structure and dynamics of the lensing galaxy.

## 4. How does the study of Einstein's Cross contribute to our understanding of the universe?

The study of Einstein's Cross and other lensing galaxies allows scientists to test and refine theories of gravity and the nature of dark matter, which are fundamental to our understanding of the universe. It also provides a unique opportunity to study the properties of distant objects, such as quasars, and the effects of their environments on their appearance.

## 5. What future research is being conducted on Einstein's Cross and lensing galaxies?

Scientists are continuously studying and monitoring Einstein's Cross and other lensing galaxies to gather more data and refine their understanding of these objects. Future research may involve using advanced telescopes and instruments to study the properties of lensing galaxies in different wavelengths of light, as well as searching for new lensing galaxies and studying their properties.